Vehicle brake lights have been mandated since the 1920's. Conventional brake light systems for vehicles include rear mounted brake lamps which are illuminated whenever the brake pedal is depressed and which are "turned-off" when the brake pedal is released. The actuation of the brake lamps is controlled by a brake switch which is mechanically linked to the vehicle's brake pedal. The brake pedal switch controls current flowing to one or more brake lights on the vehicle to warn following drivers that the vehicle is being braked.
Despite the presence of brake lights to warn drivers, a relatively large number or rear end collisions continue to occur. To help stem this problem, Congress recently enacted new legislation requiring an auxiliary, centrally located brake lamp to be placed at approximately eye level with respect to the drivers in the trailing vehicles. These new centrally located brake lamps are intended to increase the visibility of the brake light and reduce rear end collisions. Nevertheless, rear-end collisions are a continuing problem.
It has been proposed in the past to "flash" the brake lights to more effectively attract the attention of drivers in the trailing vehicles. One such system is disclosed in U.S. Pat. No. 4,663,609 in which depression of the vehicle brake pedal causes the brake lights to flash intermittently in order to attract the attention of the driver in a trailing vehicle. However, the brake lights only flash while the brake pedal is depressed. Similar systems are disclosed in U.S. Pat. No. 5,028,908 to Juang, and U.S. Pat. No. 4,403,210 to Sullivan.
These prior art brake lighting systems do not address the potentially hazardous situation that exists when a momentarily slowed vehicle is re-accelerated. When the brake pedal is released, the driver in the following vehicle is likely to begin accelerating his vehicle as well. If the driver in the leading vehicle suddenly brakes while the driver behind is accelerating, then the chances of a rear end collison are greatly increased. One possible solution to this problem is disclosed in U.S. Pat. No. 4,990,887 to Lee. A brake light system is disclosed in which brake lights are illuminated continuously as long as the brake pedal is depressed and for a predetermined duration after the brake pedal is released. This system will cause the driver in the trailing vehicle to delay prior to accelerating thereby decreasing the chances of a rear end collision. However, the brake signal is ambiguous since the driver of the trailing vehicle is unable to determine when the braking action of the leading vehicle is discontinued.